Ultrasound biomicroscopy of the eye in cystinosis

Objective: To describe the ocular ultrasound biomicroscopy (UBM) findings i n patients with cystinosis. Methods: Six patients with infantile nephropathic cystinosis, aged 16 to 25 years, and 6 controls (matched for age and spherical refractive error) wer e examined clinically and with UBM. Scleral reflectivity, corneal and iris thickness, central anterior chamber depth, angle width, trabecular meshwork to ciliary process distance, and ciliary sulcus width were measured. Results: No patient had glaucoma or posterior synechiae, but all had crysta ls in the trabecular meshwork apparent with gonioscopy. Using UBM, the corn ea and iris appeared similar in both groups, but the scleral reflectivity w as increased in patients (P = .003). The angle was narrower in patients (me an +/- SD, 20 degrees +/- 7 degrees) than controls (31 degrees +/- 5 degree s, P < .001). The anterior chamber was shallower in patients (2556 +/- 197 mu m) than controls (2968+/-284 mu m, P < .001). The ciliary sulcus was clo sed or narrow in all patients (83 +/- 112 mu m) compared with controls (339 +/- 135 mu m, P < .001), with a reduction in the trabecular meshwork to ci liary process distance. Conclusions: This report of ocular UBM findings in cystinosis demonstrated narrowing of the angle and a ciliary body configuration similar to that rep orted for plateau iris syndrome. Gonioscopy demonstrated crystals in the tr abecular meshwork. These findings may explain the predisposition of these p atients to glaucoma.